Method and apparatus for fan-folded stacking

ABSTRACT

A method and apparatus for stacking continuous envelopes into a fan-folded stack by longitudinally feeding a precreased continuous envelope sheet downwardly and horizontally feeding successive double leaf sections of the continuous envelope sheet onto a belt conveyor support and with the leaves of the continuous envelope sheet extending normal to the conveyor. A pair of laterally spaced rotary stacking mechanisms, each having two coaxial upstanding eccentrically mounted blades are connected to be driven together for actuating successive double leaf sections of the elongated continuous envelope sheet into folded generally compact association with the preceding sections of the stack on the conveyor, and such that a pair of the blades are temporarily held at a forward &#39;&#39;&#39;&#39;hold&#39;&#39;&#39;&#39; position to maintain the last sheet section in folded compact association with the stack while the other pair of blades is driven to actuate the succeeding section of the continuous envelope sheet substantially into folded compact association with the stack.

United States Patent Welch [451 July4, 1972 [54] METHOD AND APPARATUS FOR FAN- FOLDED STACKING [72] Inventor: Archibald H. Welch, Branford, Conn.

[73] Assignee: Converters Incorporated, Farmington,

Conn.

[22] Filed: Nov. 25, 1969 [21] Appl. No.: 879,804

Primary ExaminerRobert W. Michell Attorney-Prutzman, Hayes, Kalb & Chilton 57 ABSTRACT A method and apparatus for stacking continuous envelopes into a fan-folded stack by longitudinally feeding a precreased continuous envelope sheet downwardly and horizontally feeding successive double leaf sections of the continuous envelope sheet onto a belt conveyor support and with the leaves of the continuous envelope sheet extending normal to the conveyor. A pair of laterally spaced rotary stacking mechanisms, each having two coaxial upstanding eccentrically mounted blades are connected to be driven together for actuating successive double leaf sections of the elongated continuous envelope sheet into folded generally compact association with the preceding sections of the stack on the conveyor, and such that a pair of the blades are temporarily held at a forward hold position to maintain the last sheet section in folded compact association with the stack while the other pair of blades is driven to actuate the succeeding section of the continuous envelope sheet substantially into folded compact association with the stack.

9 Claims, 3 Drawing Figures PATENTEDJUL '4 I972 sum 10F 3 INVENTOR. ARCHIBALD H. WELCH ATTORNEYS PKTENTEDJUU4 I972 3,574,254

sum 3 or 3 FIG. 3

METHOD AND APPARATUS FORFAN-FOLDED STACKING BRIEF SUMMARY OF THE INVENTION The present invention relates generally to fan-folded stacking and more particularly to a method and apparatus having notable utility, for example in combination with continuous envelope assembling apparatus, for stacking continuous envelopes into a fan-folded stack.

It is a principal aim of the present invention to provide a new and improved method and apparatus for stacking continuous envelopes into a fan-folded stack.

It is another aim of the present invention to provide a new and improved method and apparatus for stacking an elongated sheet into a fan-folded stack.

It is a further aim of the present invention to provide a new and improved method and apparatus for stacking continuous envelopes into a fan-folded stack which permits removal of a selective number of the continuous envelopes from one end of the stack while the continuous envelopes are being. stacked onto the other end.

It is another aim of the present invention to provide a new and improved method and apparatus for stacking continuous envelopes in a uniform fan-folded stack useful for example for feeding the continuous envelopes at high speed through suitable tabulating equipment for addressing the envelopes.

It is a further aim of the present invention to provide a new and improved apparatus for stacking an elongated sheet into a fan-folded stack which provides automatic and unattended stacking.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

A better understanding of the invention will be obtained from the following detailed description and the accompanying drawings of an illustrative application of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a side elevation view, partly broken away and partly in section, of an embodiment of a stacking device employing the present invention;

FIG. 2 is an enlarged partial plan section view, partly broken away and partly in section, of the stacking device taken substantially along line 22 of FIG. 1; and

FIG. 3 is an enlarged elevation section view, partly broken away and partly in section taken substantially along line 33 of FIG. 2.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings in detail, wherein like numerals represent like parts, a stacking device employing the present invention is shown comprising a stacking unit and a vertically adjustable table 14 having an adjustable leg 16 at its outer or forward end and supported at its inner or rear end on a transverse rod 17 which is vertically adjustable on upright support members 18 of the stacking unit frame 20.

The table 14 comprises a horizontal conveyor 22 which provides a support for receiving the fan-folded stack as hereinafter described. The conveyor 22 comprises a pair of parallel belt conveyors having rear coaxial pulleys 30 mounted on shaft 31 for being rotated thereby, forward coaxial pulleys 32 mounted on shaft 33 and parallel belts 34 encircling the pulleys and riding on a pair of horizontal support plates 36.

A conveyor indexing mechanism comprising a one-way drive clutch 40 mounted on the pulley shaft 31 and a pneumatic clutch operating cylinder 42 is provided for indexing the conveyor and for thereby indexing the fan-folded stack formed on the conveyor. A collar 46 adjustably mounted on the piston rod 47 of the clutch operating cylinder 42 and an adjustable stop screw 48 are adjusted to provide for indexing the conveyor by an amount which is preferably approximately equal to but slightly greater than twice the thickness of a layer or leaf of the fanfolded stack.

The present invention is useful for fan-folded stacking of a continuous envelope sheet 50 as shown in FIG. 1 and wherein the continuous envelope sheet 50 is shown comprising an elongated carrier web 52 and a plurality of evenly spaced envelopes 54 attached to one side of the carrier web 52, and for example the continuous envelope sheet is constructed as disclosed and described in Archibald H. Welch U.S. Pat. No. 3,200,719 dated Aug. 17, 1965 and entitled Envelope Attaching Machine. Such continuous envelopes are typically creased at equally spaced intervals. (conventionally between the envelopes or along the folds of the envelope flaps if extended) to provide alternately oppositely facing creases or folds 56, 58 so that the continuous envelopes may be formed into a fan-folded stack which thereby permits the envelopes to be subsequently fed from the stack for example through appropriate tabulating equipment for addressing the envelopes. Alternatively the carrier web 52 could be preformed with transverse lines of perforations (not shown) to provide fold lines for fan-folded stacking the continuous envelope sheet 50.

The stacking unit 10 is provided with rear and forward guides 66, 67 for feeding the continuous envelope sheet 50 downwardly into the stacking unit from associated apparatus (not shown). The rear guide 66 is adjustably mounted on a transverse rod 68 of the stacking unit frame 20, the forward generally U-shaped guide 67 is mounted on an overhead cross piece 70 of the frame 20, and the guides 66, 67 together define a throat 71 through which the continuous envelope 50 is guided.

The precreased continuous envelope sheet 50 comprises in effect a succession of substantially identical double leaf precreased sections 72 which for the purpose of this description may be considered to be composed of forward and rear leaves 74, 76 and an intermediate forwardly facing crease 58. After each continuous envelope section 72 has passed downwardly through the throat 71 it is actuated forwardly by a pair of upright rotary blades 82 of a pair of laterally spaced stacking mechanisms 86 which are simultaneously driven by a lateral drive shaft 88 through 1:1 gearing comprising the bevel gears 89, 90. A drive sprocket 91 (FIG. 2) is mounted on an end of the drive shaft 88for driving the shaft in accordance with the speed of operation of the associated apparatus to provide for stacking the continuous envelope sheet 50 at the rate it passes through the throat 71.

Each of the stacking mechanisms 86 comprises a pair of rotatable blade assemblies 92, 93 having arms 94, 95 rotatably mounded on a fixed center shaft 96 and blade supports 97, 98 pivotally mounted on the outer ends of the arms 94, 95 respectively. The blade supports 97, 98 are biased inwardly by tension springs 99 into engagement with adjustable stops 100 which provide for setting the operative angle of the blades 82 which is preferably set so that the blades extend parallel to their axis of rotation (and also substantially perpendicular to the plane of the conveyor 22). Cam rollers 101 are rotatably mounted on the lower ends of the supports 97, 98 for engagement with a cam 102 mounted on a base plate 103 to pivot the blades outwardly against the bias of the tension springs 99 as seen in FIGS. 1 and 3 during approximately 90 of their circular motion.

Depending L-shaped abutrnents 104, 105 are mounted on the arms 94, 95 and a drive arm 106 is mounted on a drive sleeve 107 driven by the bevel gear 90 for engagement with a lower lateral projection of the abutments 104, 105. As seen in FIGS. 2 and 3 the drive arm 106 is mounted on a yoke 108 and with its inner end received within an axial slot of the sleeve 107. The yoke 108 is pivotally mounted on the drive sleeve 107 to permit limited upward pivotal movement of the drive arm (against the bias of a return torsion spring 109) from its lower active position adapted for engagement with the abutments 104, 105 and its upper inactive position, shown in broken lines in FIG. 3, out of alignment with the abutments 104, 105.

A cam 110 mounted on the base plate 103 provides for temporarily raising the drive arm 106 to thereby release the driven blade assembly and pick up the other blade assembly. More particularly the drive ann 106 provides for rotating each of the blades 82 to a hold station" 120 where the blade is released by the cam 110. As each blade assembly approaches the hold station 120 it engages and indexes the other blade assembly previously left at the hold station" and which is then picked up by the drive arm 106 to be driven around the center shaft 96 back to the hold station. Thus, each of the blades 82 is rotated to the hold station 120 and is released to remain at the hold station" until the other blade is rotated back around to the hold station."

Referring to FIG. 2, the stacking mechanisms 86 are rotated in opposite angular directions to rotate the blades 82 laterally inwardly and forwardly into engagement with the individual continuous envelope sections 72 and for actuating the sections 72 forwardly onto the trailing edge of the conveyor 22 where each continuous envelope section 72 is temporarily held in position by the pair of blades 82 at the hold stations." Also as the blades are rotated around for engagement with the rear face of the continuous envelopes the cams 102 provide for swinging the blades outwardly to ensure that they clear the outer edge of the continuous envelopes.

A pair of lateral guides 130 (of which only one is shown) are mounted on the fixed center shafts 96 of the stacking mechanisms 86 to provide for laterally guiding each continuous envelope section 72 into accurate alignment with the preceding sections of the fan-folded stack formed on the conveyor 22. Also, the stacking mechanisms 86 are mounted on the pair of transverse rods 68, 132 to provide for laterally positioning the stacking mechanisms in accordance with the width of the continuous envelope, and for this purpose the stacking mechanisms have depending plates 134 for laterally shifting the bevel gears 89 and 90 with the stacking mechanisms.

A cam 140 is mounted on the drive shaft 88 for operating a pneumatic valve 142 for the conveyor indexing cylinder 42, and the cam 140 is mounted to actuate the valve 142 and thereby index the conveyor preferably just as the active blades 82 reach the hold stations" 120. Thus, the fan-folded stack formed on the conveyor is indexed forwardly an amount approximately equal to twice the thickness of the continuous envelopes as the active blades actuate a continuous envelope section 72 onto the trailing edge of the conveyor. In addition an adjustably mounted upper positioning finger 144 operated by pneumatic cylinder 146 and a lower positioning finger 148 operated by pneumatic cylinder 150 are connected in parallel with the pneumatic cylinder 42 to provide for engaging the upper and lower edges of the fan-folded stack on the conveyor to ensure that the last continuous envelope section is positioned in proper folded generally compact association with the preceding continuous envelope sections of the stack. The cylinder 146 and finger assembly are also pivotally mounted for adjusting where the finger 144 engages the fan-folded stack and which is preferably slightly below the upper fold.

In operation the two pairs of blades 82 of the stacking mechanisms 86 are driven to engage the rear face of the rear leaf of successive sections 72 of the continuous envelope sheet and to thereby actuate the continuous envelope sections forwardly to the rear end of the conveyor, during which motion the upper edges of the operative pair of blades 82 engage the upper crease between the adjacent forward and rear sections 72 to carry the forward section 72 to the conveyor 22. The conveyor is, however, preferably vertically positioned so that as the continuous envelope section 72 reaches the conveyor it becomes supported on the conveyor and the upper crease connecting the successive continuous envelope sections 72 is slightly above the upper edges of the blades 82.

The blades 82 at the hold stations" 120 provide a support for the rear end of the fan-folded stack (which is supported on the conveyor with the continuous envelope sheet sections substantially normal to the plane of the conveyor) until the other pair of blades are rotated to pick up the succeeding continuous envelope section 72 and actuate it forwardly to the stack, whereupon the pair of blades 82 at the hold station" 120 are rotated laterally out of the stack, and for this reason the blades 82 are preferably provided with a slippery teflon-reinforced fiber glass outer surface to avoid distorting the stack as the blades are laterally withdrawn. The plates 103 on which the cams 102 and are mounted are made angularly adjustable to provide for angularly positioning the hold stations of the blades, and it has been found that the hold stations are preferably angularly offset slightly as best shown in FIG. 2 to provide a slight forward component of the blade motion as the blades are laterally withdrawn from the continuous envelope stack.

Thus, the stacking method and apparatus of the present invention provides for automatically and accurately stacking an elongated sheet, such as a continuous envelope sheet, into a fan-folded stack and so that the stacking operation may continue while a portion of the stack is removed (as for example by cutting the cOntinuous envelope sheet along one of the upper stack folds). Also, a suitable back-up" plate 156 is preferably provided for supporting the forward end of the continuous envelope stack on the conveyor and may be suitably repositioned on the conveyor when a portion of the stack is removed.

In addition the stacking method and apparatus of the present invention has notable utility in providing for accurate fan-folded stacking of continuous envelopes for subsequent use, for example, for feeding the envelopes at a high speed through tabulating equipment for addressing the envelopes.

As will be apparent to persons skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosure can be made without departing from the teachings of the present invention.

I claim:

1. A stacking device for stacking into a fan-folded stack an elongated sheet formed to provide oppositely facing laterally extending and longitudinally spaced folds providing a succession of double leaf folded sheet sections with connected forward and rear leaves, comprising a support for receiving the fan-folded stack, means for feeding the sheet longitudinally downwardly rearwardly of the support with said lateral folds extending generally horizontally, and a stacking device mounted rearwardly of the support for receiving the sheet as it is fed longitudinally downwardly and for stacking the sheet sections in folded generally compact association on the support and with the sheet sections of the stack mounted upright on the support, the stacking device comprising at least one rotatable stacker having at least one elongated blade and blade drive means for rotating the blade about a generally upright axis of rotation and with the longitudinal axis of the blade extending generally upright and offset from said axis of rotation of the blade for swinging the blade generally horizontal around an axis extending generally perpendicular to the laterally extending folds of the elongated sheet and generally perpendicular to the support, the blade drive means being operable for swinging the elongated blade generally horizontally around into positive engagement with the rear leaf of a sheet section with the longitudinal axis of the blade extending generally perpendicular to the laterally extending folds of the elongated sheet for transporting the sheet section generally horizontally forwardly from the downwardly fed sheet into folded generally compact association with the preceding sheet sections of the stack on the support and for thereafter withdrawing the blade laterally from the stack and back around into engagement with a succeeding sheet section.

2. A stacking device according to claim 1 wherein the rotatable stacker comprises two of said elongated blades rotated by said drive means about said axis of rotation for respectively engaging and transporting alternate successive sheet sections forwardly into said folded generally compact association with the preceding sheet sections of the stack.

3. A stacking device according to claim 2 wherein the drive means is operable for sequentially swinging the blades to a forward hold position providing for retaining the sheet section engaged thereby in a folded generally compact association with the stack while the other blade is swung to engage and transport a succeeding sheet section forwardly into substantial folded generally compact association with the preceding sheet sections of the stack.

4. A stacking device according to claim 3 wherein the drive means comprises a rotatable drive arm engageable with the blades for swinging the blade and mounted for pivotal movement about an axis extending transversely of its axis of rotation for selectively releasing the blades and cam means for pivoting the drive arm for selectively alternately releasing the blades at said forward "hold" position.

5. A stacking device according to claim 1 wherein the stacking unit comprises two of said rotatable stackers having elongated blades respectively with spaced parallel axes of rotation and wherein the blade drive means of the rotatable stackers are connected for swinging the blades in synchronism.

6. A stacking device according to claim 5 wherein each of the rotatable stackers comprises two elongated blades providing two of said pairs of blades with each pair composed of a blade of each stacker swung in synchronism for transporting a sheet section forwardly into folded generally compact association with the preceding sheet sections of the stack.

7. A stacking device according to claim 5 wherein the fold connecting the double leaf sections is at the top of the stack formed on the support, and wherein the blades have longitudinal dimensions for engagement with the upper connecting fold between successive forward and rear sheet sections for supporting said forward sheet section as it is transported forwardly by the blades into generally compact association with the preceding sheet sections of the stack.

8. A method for stacking into a fan-folded stack an elongated continuous envelope sheet formed to provide oppositely facing laterally extending and longitudinally spaced folds providing a succession of folded double leaf sheet sections with connected forward and rear leaf portions, comprising the steps of providing a generally horizontal support for receiving the fan-folded stack, longitudinally feeding the continuous envelope sheet generally downwardly rearwardly of the support with the folds extending generally horizontally, and swinging elongated blades generally horizontally around an axis of rotation extending generally perpendicular to the laterally extending folds of the elongated sheet and generally perpendicular to the support and with the blades extending generally parallel to and offset from their axis of rotation for positively engaging the rear leafs of the sheet sections in sequence with the blades and transporting the sheet sections with the blades one at a time generally horizontally forwardly onto the support into folded generally compact association with the preceding sheet sections of the stack and with the folded sections of the continuous envelope sheet mounted upright on the support and individually withdrawing the blades laterally from the stack and returning each withdrawn blade back around into engage ment with the rear leaf of a succeeding sheet section.

9. A method according to claim 8 wherein the fold connecting the double leaf sections of the continuous envelope sheet is at the top of the stack formed on the support, and wherein the step of transporting the double leaf sections generally horizontally forwardly with the blades comprises supporting the sheet sections through engagement of the swinging blades with the folds between adjacent forward and rear sections while transporting the sheet sections generally horizontally forwardly into generally compact association with the preceding sheet sections of the stack. 

1. A stacking device for stacking into a fan-folded stack an elongated sheet formed to provide oppositely facing laterally extending and longitudinally spaced folds providing a sucCession of double leaf folded sheet sections with connected forward and rear leaves, comprising a support for receiving the fan-folded stack, means for feeding the sheet longitudinally downwardly rearwardly of the support with said lateral folds extending generally horizontally, and a stacking device mounted rearwardly of the support for receiving the sheet as it is fed longitudinally downwardly and for stacking the sheet sections in folded generally compact association on the support and with the sheet sections of the stack mounted upright on the support, the stacking device comprising at least one rotatable stacker having at least one elongated blade and blade drive means for rotating the blade about a generally upright axis of rotation and with the longitudinal axis of the blade extending generally upright and offset from said axis of rotation of the blade for swinging the blade generally horizontal around an axis extending generally perpendicular to the laterally extending folds of the elongated sheet and generally perpendicular to the support, the blade drive means being operable for swinging the elongated blade generally horizontally around into positive engagement with the rear leaf of a sheet section with the longitudinal axis of the blade extending generally perpendicular to the laterally extending folds of the elongated sheet for transporting the sheet section generally horizontally forwardly from the downwardly fed sheet into folded generally compact association with the preceding sheet sections of the stack on the support and for thereafter withdrawing the blade laterally from the stack and back around into engagement with a succeeding sheet section.
 2. A stacking device according to claim 1 wherein the rotatable stacker comprises two of said elongated blades rotated by said drive means about said axis of rotation for respectively engaging and transporting alternate successive sheet sections forwardly into said folded generally compact association with the preceding sheet sections of the stack.
 3. A stacking device according to claim 2 wherein the drive means is operable for sequentially swinging the blades to a forward ''''hold'''' position providing for retaining the sheet section engaged thereby in a folded generally compact association with the stack while the other blade is swung to engage and transport a succeeding sheet section forwardly into substantial folded generally compact association with the preceding sheet sections of the stack.
 4. A stacking device according to claim 3 wherein the drive means comprises a rotatable drive arm engageable with the blades for swinging the blade and mounted for pivotal movement about an axis extending transversely of its axis of rotation for selectively releasing the blades and cam means for pivoting the drive arm for selectively alternately releasing the blades at said forward ''''hold'''' position.
 5. A stacking device according to claim 1 wherein the stacking unit comprises two of said rotatable stackers having elongated blades respectively with spaced parallel axes of rotation and wherein the blade drive means of the rotatable stackers are connected for swinging the blades in synchronism.
 6. A stacking device according to claim 5 wherein each of the rotatable stackers comprises two elongated blades providing two of said pairs of blades with each pair composed of a blade of each stacker swung in synchronism for transporting a sheet section forwardly into folded generally compact association with the preceding sheet sections of the stack.
 7. A stacking device according to claim 5 wherein the fold connecting the double leaf sections is at the top of the stack formed on the support, and wherein the blades have longitudinal dimensions for engagement with the upper connecting fold between successive forward and rear sheet sections for supporting said forward sheet section as it is transported forwardly by the blades into generally compact association with the preceding sheet sections of the stack. Pg,17
 8. A method for stacking into a fan-folded stack an elongated continuous envelope sheet formed to provide oppositely facing laterally extending and longitudinally spaced folds providing a succession of folded double leaf sheet sections with connected forward and rear leaf portions, comprising the steps of providing a generally horizontal support for receiving the fan-folded stack, longitudinally feeding the continuous envelope sheet generally downwardly rearwardly of the support with the folds extending generally horizontally, and swinging elongated blades generally horizontally around an axis of rotation extending generally perpendicular to the laterally extending folds of the elongated sheet and generally perpendicular to the support and with the blades extending generally parallel to and offset from their axis of rotation for positively engaging the rear leafs of the sheet sections in sequence with the blades and transporting the sheet sections with the blades one at a time generally horizontally forwardly onto the support into folded generally compact association with the preceding sheet sections of the stack and with the folded sections of the continuous envelope sheet mounted upright on the support and individually withdrawing the blades laterally from the stack and returning each withdrawn blade back around into engagement with the rear leaf of a succeeding sheet section.
 9. A method according to claim 8 wherein the fold connecting the double leaf sections of the continuous envelope sheet is at the top of the stack formed on the support, and wherein the step of transporting the double leaf sections generally horizontally forwardly with the blades comprises supporting the sheet sections through engagement of the swinging blades with the folds between adjacent forward and rear sections while transporting the sheet sections generally horizontally forwardly into generally compact association with the preceding sheet sections of the stack. 